Apparatus and method for placing spacer sticks on a board stack

ABSTRACT

An apparatus for placing out spacer sticks on a board stack ( 1 ) comprises a feeder device ( 5 ) for the individual discharge of spacer sticks ( 3 ). The feeder device ( 5 ) is placed in association with one short end of the stack ( 1 ). Further, the apparatus has a conveyor device which is located above the stack ( 1 ) for conveying spacer sticks ( 3 ) from the feeder device ( 5 ) to positions over the stack ( 1 ). At least those parts of the conveyor device which are located under the spacer sticks ( 3 ) are disposed to be movable in the lateral direction between advancement positions over the stack ( 1 ) and release positions outside the stack. As a result, the spacer sticks ( 3 ) are movable from position over the stack ( 1 ) to positions where they rest on the stack ( 1 ). A method for placing spacer sticks on a board stack is also disclosed.

TECHNICAL FIELD

The present invention relates to an apparatus for placing spacer sticks(also known as dunnage) on a board stack, and comprising a feeder deviceFor the individual feeding of spacer sticks, the feeder device beingplaced in association with one short end of the stack, and a conveyordevice located over the stack for conveying spacer sticks from thefeeder device to positions over the stack.

The present invention also relates to a method for placing spacer stickson a board stack, comprising the steps that the spacer sticks aredischarged individually from a feeder device to a conveyor device, thatthe spacer sticks are carried by at least one carrier device locatedbeneath the spacer sticks along a path over the stack and that thespacer sticks, when they are brought to positions substantially straightabove their intended positions on the stack, are transferred to them.

BACKGROUND ART

In the stacking of boards, a whole layer of boards is laid on the top ofa board stack which is under construction by means of an off-loaderwhich moves transversely of the longitudinal direction of the boards toa position in over the board stack. There, the layer of boards isoff-loaded on subjacent spacer sticks whose longitudinal directions aretransversely directed in relation to the longitudinal direction of theboards. Thus, the off-loader is placed along one longitudinal side ofthe board stack which is being constructed.

The board stack which is being built up is placed on a verticallyadjustable substrate which is gradually lowered as the height of theboard stack increases so that the level of the uppermost layer in theboard stack is thereby throughout substantially unchanged.

For placing spacer sticks on the upper side of a recently off-loadedlayer of boards, use is normally made of two chains which run in overthe stack and in its longitudinal direction, and in parallel with oneanother, and at such a height over the stack that the off-loader canpass under them for off-loading a layer of boards. The chains have hookswhich, on the lower parts of the chains, are rearwardly open in thedirection of travel. The chains are employed for conveying spacer sticksfrom a feeder device to positions over the stack. By the employment ofvertically movable abutments, the spacer sticks are caused to releasefrom the hooks and fall down on the upper side of the stack.

A spacer stick layer device of this type comprises a considerablequantity of complex mechanical machinery. The distances between adjacentspacer sticks cannot readily be changed, and nor can spacer sticks ofvarying dimensions be handled. Finally, the work rate is too low.

For laying out spacer sticks, an apparatus is further known in the artby means of which the spacer sticks are placed out on a substrate on theopposite side of the board stack in relation to the off-loader and fromthence are lifted and displaced by means of suitable gripping members inover the board stack where the spacer sticks are lowered and depositedon the board stack.

An apparatus of this type operates slowly because of the long transportdistances which are required on laying out the spacer sticks. Further,it is difficult to get at the finished stack, since it is surrounded bymachinery.

PROBLEM STRUCTURE

The present invention has for its object to design the apparatus and themethod intimated by way of introduction such that at least the onelongitudinal side of a board stack can be kept wholly fee of machineryso that the board stack is thereby readily accessible. Further, thepresent invention has for its object to design the apparatus such thatthis may work at a very high work rate and with good operationalreliability, and also permit convenient modification of the number,mutual spacing and dimensions of the spacer sticks.

SOLUTION

The objects forming the basis of the present invention will be attainedregarding the apparatus if this is characterized in that at least partsof the conveyor device located beneath the spacer sticks are disposed tobe movable in the lateral direction from advancement positions over thestack to release positions outside the stack, whereby the spacer sticksmay readily be transferred from their positions located over the stackto positions where they rest on the stack.

Furthermore, the objects forming the basis of the present invention willbe attained regarding the method if this is characterised in that thespacer sticks are moved along and in the longitudinal direction of thecarrier device and, when they have reached their positions above theintended positions on the stack, are stopped and the carrier device isreleased from the spacer sticks which are transferred to their intendedpositions.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will now be described in greater detailhereinbelow, with particular reference to the accompanying Drawings. Inthe accompanying Drawings:

FIG. 1 is a schematic, greatly simplified vertical side elevation of theapparatus according to the present invention;

FIG. 2 is a simplified end elevation of the apparatus according to thepresent invention in a first working step during the laying-out of thespacer sticks;

FIG. 3 is a view corresponding to that of FIG. 2 in a later working stepin the laying-out of the spacer sticks;

FIG. 4 is a view corresponding to that of FIG. 2, a further working stephaving been completed in the laying-our of the spacer sticks;

FIG. 5 is a view corresponding to that of FIG. 2, yet a further workingstep having been completed in the laying-out of the spacer sticks; and

FIG. 6 is a view corresponding to that of FIG. 2 showing the apparatuswhen the spacer sticks have been placed on the upper side of the stack.

DESCRIPTION OF PREFERRED EMBODIMENT

The accompanying Drawings show only those components which directlycarry out the laying-out of the spacer sticks on the upper side of theboard stack. Thus, the Drawings have omitted the beam frame whichsupports the above-mentioned components, as well as the guides and drivemeans required for their movements.

In FIG. 1, reference numeral 1 relates to a board stack which is in theprocess of being built up from boards 2 which are arranged in layers anda number of spacer sticks 3 are located between the layers. The boardstack 1 rests on a substrate 4 which is movable in the verticaldirection and which is gradually lowered as the board stack 1 is builtup so that the uppermost layer of boards 2 is kept at a substantiallyconstant level.

The boards 2 are displaced by layers in over the board stack by means ofan off-loader (not shown) and are off-loaded on spacer sticks placedthere. In FIG. 2, this takes place from the right.

In connection with the one short end of the board stack 1, there isdisposed a feeder device 5 whose feeding direction is intimated by thearrow 6, the spacer sticks being fed out individually and with theirlongitudinal direction horizontal and transversely directed in relationto the feeding direction 6.

In its most generic form, the present invention entails that there aredisposed, in over the stack 1 and substantially parallel with itslongitudinal direction, elongate carrier devices which are included in aconveyor device and which, with their one end, extend to the feederdevice 5 and which, with their opposite end, extend at least so faralong the stack 1 where spacer sticks 3 are to be placed. The carrierdevices have no fixed positions for the spacer sticks 3, but these canbe transported carried by and along the carrier devices in basically anyoptional number and with any optional spacing. The transport speed alongthe carrier devices for the spacer sticks 3 is the same for all of thespacer sticks which are to lie in the same layer on the stack 1, but mayotherwise be varied within broad limits.

Alternatives are also conceivable where only one carrier device isemployed along either of the longitudinal sides of the stack 1. In orderto prevent the end portions of the spacer sticks 3 not carried by thecarrier device from falling down on the stack, there is provided, overthe stack, an elongate hold-down device, for example a belt or chainconveyor or slide rail so that the spacer sticks are fixedly clampedbetween the carrier device and the hold-down device when they are movedalong the carrier device with their longitudinal direction transverselydirected, preferably approximately at right angles, to the longitudinaldirection of the carrier device.

When the number of spacer sticks 3 which are to be located on theuppermost board layer of the stack 1 has been transported along thecarrier device/devices to positions straight above the positions theyare to assume on the stack 1, the movement of all of the spacer sticksis arrested simultaneously, whereafter the spacer sticks are transferreddownwards, preferably by force of gravity, to their final positions onthe stack.

In one alternative, the vertical transfer of the spacer sticks 3 totheir final positions on the stack 1 is made possible in that the twocarrier devices are displaced horizontally sideways from thefeeding/transport positions in over the stack 1 to release positionsoutside the stack, whereby the spacer sticks 3 can pass down between thecarrier devices. On the lateral movement of the carrier devices, thespacer sticks are held so that they cannot be displaced in theirlongitudinal direction (accompany either or both of the carrierdevices).

As an alternative to the substantially horizontal lateral displacementof the carrier devices away from one another, it is also possible toturn the spacer sticks 3 a certain angle in a substantially horizontalplane so that the opposite ends of the spacer sticks are free from themutually facing edges of the carrier devices, whereafter the spacersticks are lowered to a level below the carrier devices, they then beingturned back through approximately the same angle before they arereleased down on the stack

In the alternative with only one carrier device, the carrier device andthe hold-down device are separated from one another in the verticaldirection so that the ungripped ends of the spacer sticks rock down onthe stack 1. In this position, the spacer sticks are fixed in theirlongitudinal direction, whereafter the carrier device is laterallydisplaced to the release position so that the spacer sticks can fallcompletely down on the stack

Concrete embodiments of the present invention will now be described withreference to the accompanying Drawings.

Above the board stack 1, there is disposed a conveyor device with twoconveyors 7 and 8 which extend approximately parallel with thelongitudinal sides of the stack 1 in over the stack 1. The conveyorsserve the function of carrier devices and are suitably designed as beltconveyors where the conveyor belts have layers facing towards the spacersticks 3 which, on the one hand, afford high friction against the spacersticks and which, on the other hand, are somewhat resiliently yieldableso that the spacer sticks can be pressed slightly therein if the spacersticks are pressed against the conveyors 7 and 8. The conveyor 7 has abelt 11 running over two rollers 9 and 10. The conveyor 8 has acorresponding construction. The two conveyors 7 and 8 run withsynchronous speed and can, therefore, receive spacer sticks dischargedfrom the feeder device 5, the spacer sticks being transported withretained orientation in the direction of the arrow 6 along the twoconveyor. The and surfaces of spacer sticks placed on the conveyors areshown in FIG. 1.

The distance between the spacer sticks resting on the conveyors mayreadily be modified by a modification of the relationship between thelinear speed of advancement of the conveyors and the discharge rate ofthe individual spacer sticks out of the feeder device 5.

The two conveyors 7 and 8 are movably secured in a frame (not shown onthe Drawings) for the apparatus according to the invention and are atleast movable laterally in a substantially horizontal direction betweenthe advancement positions illustrated in FIGS. 2 and 3 and the releasepositions illustrated in FIG. 6. In the advancement positions, theconveyors are, as is apparent from FIGS. 2 and 3, disposed in over theupper side of the stack and approximately along and slightly insideopposing edges of the stack. In the release positions, the conveyors 7and 8 are located completely outside the stack seen in the lateraldirection.

The transfer of the conveyors 7 and 8 between the advancement positionsand the release positions and back may be realised by employing linearguides and piston and cylinder units, but may also be realised in thatthe conveyors are pendulum-suspended and are laterally moved in apendulum motion.

In the embodiment shown on the Drawings, the hold-down devices aredesigned as a third conveyor 12 which is placed parallel with and aslight distance above one of the conveyors 7 and 8 when these arelocated in the advancement position. The third conveyor 12 is movable inthe vertical direction and, as is apparent from FIGS. 2 and 3,displaceable into abutment against the spacer sticks 3 resting on theconveyors 7 and 8.

When the different conveyors 7, 8 and 12 are in the positionsillustrated in FIG. 3, the conveyor 8 is laterally displaced to theposition according to FIG. 4, the spacer sticks being fixedly clampedbetween the conveyors 7 and 12 so that they freely hang out from thesetwo conveyors.

When the third conveyor 12 is lifted back to the starting position, thespacer stick 3 will rock and pivot so that its right-hand end in theFigures falls down on the uppermost layer of boards 2 in the board stack1 and rests on it. In the last step of the deposition of the spacersticks, the conveyor 7 is laterally displaced to the positionillustrated in FIG. 6 so that the opposite ends of the spacer stacks 3also fall down on the upper side of the stack 1.

In order to ensure that the spacer sticks 3 do not accompany the lateraldisplacement when the conveyor 7 is moved, it is possible to provide, inthe region at reference numeral 13, a longitudinal rail which has asmooth upper side and which extends along the entire length of the upperpart of the conveyor 7 and is placed, in the vertical direction, in sucha manner that, with the spacer sticks 3 horizontal, it has a shorterdistance to the undersides of the spacer sticks while it abuts againstand slightly lifts the spacer sticks 3 from the conveyor 7 when theopposite ends of the spacer sticks have fallen or been pivoted down onthe upper side of the stack 1 and both the conveyor 7 and the rail 13are laterally displaced to the release position. In that the rail 13 hasslight friction against the spacer sticks 3 (which, on the other hand,is not the case for the belt of the conveyor 7), the risk is reducedthat the spacer sticks might possibly be entrained in the lateralmovement.

In another alternative, the conveyor 8 is also movable in the verticaldirection so that, in the position according to FIG. 5, it may beshifted in to its starting position and there be lowered so that it isapplied against the lower ends of the spacer sticks 3 so that these areclamped between the conveyor 8 and the upper side of the board stack 1.

On the infeed of the spacer sticks on the conveyors 7 and 8, it has beenshown in the Figures that the third conveyor 12 is to be located in itsraised position. However, this is not necessary, but the conveyor 12 maybe driven synchronously with the two other conveyors so that the spacersticks 3 are thereby fixedly clamped between the conveyor belts in theconveyors 7 and 12. Hereby, the work rate will be substantiallyincreased and, further, the risk will be avoided that the spacer stickslose their positioning when the conveyors are stopped when the spacersticks carried on the conveyors are located straight above theirintended positions an the upper side of the stack 1.

According to the present invention, it is also possible to employ afourth conveyor which corresponds to the third conveyor 12 and which isplaced over the conveyor 8. This fourth conveyor also improves thepositioning of the spacer sticks by clamping the spacer sticks betweenitself and the subjacent conveyor 8 in connection with acceleration orretardation movements of the conveyors.

If a fourth conveyor is employed, its movement space in the verticaldirection may be so great that it can be applied against the lower endof inclined spacer sticks according to FIG. 5 when the conveyor 8 islaterally displaced to its release position.

The hold-down device need not be designed as the third conveyor 12 orpossibly the fourth conveyor, but may, in an alternative version, be inthe form of an elongate rail which is movable in the vertical directionand placed analogous with the conveyor 12 so that it may be appliedagainst the upper sides of the spacer sticks 3 carried on the conveyors7 and 8 when these are located in positions according to FIGS. 3 and 4.

Correspondingly, a vertically displaceable rail can replace the clampingfunction which may be allocated to the conveyor 8 in the positionaccording to FIG. 5.

In a further alternative, the hold-down device nay be designed aselongate stop bars which are placed in connection with the end surfacesof the spacer sticks 3 in such vertical positions that the carrierdevices can pass under them on the displacement from the advancementposition to the release position, but be sufficiently low for them to bestruck by the spacer sticks 3 if these were to be displaced in thelongitudinal direction.

It is also possible to form the hold-down device so that it can impart alimited longitudinal movement to the spacer sticks 3. As a result, insuch embodiments where the spacer sticks 3 rest on two carrier devices,e.g. the two conveyors 7 and 8, one of these may be made fixed in thelateral direction since the spacer sticks instead are longitudinallydisplaced so far that their ends are free of this field carrier device.

In the foregoing, it has been described how the carrier devices aredesigned as conveyors on which the spacer sticks 3 rest. An alternativecarrier device is an elongate slide rail which, on its side facingtowards the spacer sticks, has a coating consisting of a material of lowfriction in relation to the spacer sticks. For driving the spacer sticksalong the slide rails, use is made of one or two conveyors (e.g. theconveyor 12 above) placed over the spacer sticks 3 and clamping thespacer sticks between itself and the subjacent slide rail. Both theslide rail and the co-operating conveyor may be movable in the verticaldirection for releasing the spacer sticks 3.

A construction in which the conveyors are placed undermost and thusfunction as carrier devices and in which the slide rails are placeduppermost is also possible.

In the foregoing, it has been described how the spacer sticks 3 arecarried by carrier devices in the form of slide rails or conveyors 7 and8 at opposite end portions. However, it is also possible to employ asingle career device which may be placed at one end of the spacer sticksor in the central region of the spacer sticks.

When the carrier device (conveyor or slide rail) is placed at endportions of the spacer sticks, it must be combined with a hold-downdevice (slide rail or conveyor, respectively) so that the operationalconditions will be as shown in FIG. 4 and the laying-out of the spacersticks as shown in FIG. 5.

When the carrier device is placed under the central region of the spacersticks, the carrier device may be made so wide that a hold-down devicemay possibly be dispensed with.

1. An apparatus for placing a selectable number of spacer sticks withselectable mutual distance on top of a board stack having first andsecond longitudinal sides and first seconds ends, the apparatuscomprising: a feeder device for individually feeding spacer sticks witha selectable rate of feeding, the feeder device being located inassociation with the first end of the board stack; a conveyor deviceprovided above the board stack and configured to receive the spacersticks as fed by the feeder device and to transport them with aselectable speed of transportation to locations above their intendedlocations on the board stack; the conveyor device having at least onefirst and one second conveyor, each having upper and lower runs, thefirst and second conveyors being, in transport positions, located abovethe board stack and along opposite longitudinal sides thereof forsupporting, on their upper runs, opposite end portions of the spacersticks, the first and second conveyors being laterally displaceableapart to release positions where the spacer sticks are free to passdownwardly between them to their intended positions on top of the boardstack.
 2. The apparatus as claimed in claim 1, wherein the secondconveyor is movable in a vertical direction and into abutment againstlower end portions of the spacer sticks which, with the lower endportions, rest on the stack and which, with the upper end portions, reston the first conveyor.
 3. The apparatus as claimed in claim 1, whereinhold down members in the form of belt conveyors are provided at both thefirst and at the second conveyors.
 4. The apparatus as claimed in claim1, wherein one of the first and second conveyors and an elongate slidewall are disposed to grip between them and advance the spacer sticks,the conveyor and the elongate slide having longitudinal directions whichare substantially parallel with one another and with the longitudinaldirection of the stack, and being disposed over the stack and along onelongitudinal edge thereof.
 5. The apparatus as claimed in claim 1,wherein at least one of the first and second conveyors is a beltconveyor having a material layer facing towards the spacer sticks whichis resiliently yieldable and relatively soft in order to permit thespacer sticks, during advancement, to be at least partly impressedtherein.
 6. The apparatus as claimed in claim 1, wherein two elongatedstop bars are provided in connection with opposite end surfaces of thespacer sticks when the spacer sticks rest on the first and secondconveyors, the stop bars being located, in the vertical direction, so asto permit passage, beneath the stop bars, of the conveyors when theconveyors are laterally displaced to their release positions, but to behit by the end surfaces of the spacer sticks if one or more of thespacer sticks were to accompany such lateral movement.
 7. The apparatusas claimed in claim 1, wherein an elongated slide rail is provided overthe board stack and substantially in parallel with the first conveyorwhen in transport position, said slide rail being located verticallysuch that, when the second conveyor has been displaced to its releaseposition and the second end portions of the spacer sticks originallysupported on the second conveyor have fallen down onto the board stack,the first end portions of the spacer sticks are supported on the sliderail instead of on the first conveyor, said slide rail being laterallydisplaceable together with the first conveyor.
 8. The apparatus asclaimed in claim 7, wherein the elongated slide rail has a surfacefacing towards the spacer sticks which is of low friction vis-á-vis thespacer sticks.
 9. The apparatus as claimed in claim 1, wherein a holddown member is provided to prevent longitudinal displacement of thespacer sticks when at least one of the first and second conveyors arelaterally displaced to its release position.
 10. The apparatus asclaimed in claim 9, wherein the hold down member is a belt conveyor. 11.The apparatus as claimed in claim 9, wherein the hold down device is inthe form of an elongate rail.
 12. The apparatus as claimed in claim 9,wherein the hold down device is in the form of an elongate rail whichis. substantially parallel with the conveyors and which is movable inthe vertical direction and into abutment from above against end portionsof the spacer stick facing away from the conveyors.
 13. An apparatus forplacing spacer sticks on top of a board stack, comprising: a feederdevice for individually feeding spacer sticks, the feeder device beinglocated at an end of the board stack; a conveyor device configured toreceive the spacer sticks as fed by the feeder device and to transportthe spacer sticks to locations above their intended locations on top ofthe board stack; the conveyor device having at least one first and onesecond conveyor, the conveyors being located, in transport positions,above the board stack and along its opposed longitudinal sides forsupporting opposite end portions of the spacer sticks, the first andsecond conveyors being laterally displaceable apart to release positionswhere the spacer sticks may pass between said first and second conveyorsto the spacer sticks intended positions on top of the board stack. 14.The apparatus as claimed in claim 13, wherein a hold down member isprovided to prevent longitudinal displacement of the spacer sticks whenat least one of the first and second conveyors are laterally displacedto its release position.
 15. The apparatus as claimed in claim 13,wherein two elongated stop bars are provided in connection with oppositeend surfaces of the spacer sticks when the spacer sticks rest on thefirst and second conveyors, the stop bars being located, in the verticaldirection, so as to permit passage, beneath the stop bars, of theconveyors when the conveyors are laterally displaced to their releasepositions, but to be hit by the end surfaces of the spacer sticks if oneor more of the spacer sticks were to accompany such lateral movement.16. The apparatus claimed in claim 13, wherein an elongated slide railis provided over the board stack and substantially in parallel with thefirst conveyor when in transport position, said slide rail being locatedvertically such that, when the second conveyor has been displaced to itsrelease position and the second end portions of the spacer sticksoriginally supported on the second conveyor have fallen down onto theboard stack, the first end portions of the spacer sticks are supportedon the slide rail instead of on the first conveyor, said slide railbeing laterally displaceable together with the first conveyor.
 17. Anapparatus for placing spacer sticks on top of a board stack comprising:a feeder device for individually feeding spacer sticks, the feederdevice being located at an end of the board stack; a conveyor deviceconfigured to receive the spacer sticks as fed by the feeder device andto transport the spacer sticks to locations above their intendedlocations on top of the board stack; the conveyor device having at leastone lower and one upper conveyor located, in transport positions, abovethe board stack and along one longitudinal side of the board stack fornipping end positions of the spacer sticks as fed by the feeder devicebetween the lower and upper conveyors, said upper conveyor beingdisplaceable upwardly to a release position and said lower conveyorbeing displaceable laterally away from the board stack to a releaseposition where the end portions of the spacer sticks are free to falldown onto the board stack.
 18. The apparatus as claimed in claim 17,wherein a hold down member is provided to prevent longitudinaldisplacement of the spacer sticks when the lower conveyor is laterallydisplaced to its release position.
 19. The apparatus as claimed in claim17, wherein two elongated stop bars are provided in connection withopposite end surfaces of the spacer sticks when the spacer sticks reston the lower conveyor, the stop bars being located, in the verticaldirection, so as to permit passage, beneath the stop bars, of theconveyor when the conveyors are laterally displaced to their releasepositions, but to be hit by the end surfaces of the spacer sticks if oneor more of the spacer sticks were to accompany such lateral movement.20. An apparatus for placing spacer sticks on top of a board stackcomprising: a feeder device for individually feeding spacer sticks, thefeeder device being located at an end of the board stack; a conveyordevice configured to receive the spacer sticks as fed by the feederdevice and to transport the spacer sticks to locations above theirintended locations on top of the board stack; the conveyor device havingat least one first and one second conveyor, the conveyors being located,in transport positions, above the board stack and along its opposedlongitudinal sides for supporting opposite end portions of the spacersticks, the first and second conveyors being laterally displaceableapart to release positions where the spacer sticks may pass between saidfirst and second conveyors to their intended positions on the top of theboard stack; and an elongated hold down member extending above and alongthe first conveyor in the transport position thereof, said hold downmember having a lower position in which end portions of the spacersticks are clamped between the hold down member and the first conveyorand an elevated position where the end portions of the spacer sticks arefree of the hold down member.
 21. The apparatus as claimed in claim 20,wherein said hold down member prevents longitudinal displacement of thespacer sticks when at least one of the first and second conveyors arelaterally displaced to its release position.
 22. The apparatus asclaimed in claim 20, wherein two elongated stop bars are provided inconnection with opposite end surfaces of the spacer sticks when thespacer sticks rest on the first and second conveyors, the stop barsbeing located, in the vertical direction, so as to permit passage,beneath the stop bars, of the conveyors when the conveyors are laterallydisplaced to their release positions, but to be hit by the end surfacesof the spacer sticks if one or more of the spacer sticks were toaccompany such lateral movement.
 23. The apparatus as claimed in claim20, wherein an elongated slide rail is provided over the board stack andsubstantially in parallel with the first conveyor when in transportposition, said slide rail being located vertically such that, when thesecond conveyor has been displaced to its release position and thesecond end portions of the spacer sticks originally supported on thesecond conveyor have fallen down onto the board stack, the first endportions of the spacer sticks are supported on the slide rail instead ofon the first conveyor, said slide rail being laterally displaceabletogether with the first conveyor.
 24. An apparatus for placing spacersticks on top of a board stack comprising: a feeder device forindividually feeding spacer sticks, the feeder device being located atan end of the board stack; a conveyor device configured to receive thespacer sticks as fed by the feeder device and to transport the spacersticks to locations above their intended locations on top of the boardstack; the conveyor device having at least one first and one secondconveyor, the conveyors being located, in transport positions, above theboard stack and along its opposed longitudinal side for supportingopposite end positions of the spacer sticks, the first and secondconveyors being laterally displaceable apart to release positions wherethe spacer sticks may pass between said first and second conveyors totheir intended positions on top of the board stack; and at least oneelongated stop member arranged along at least the first conveyor and inalignment with the end surfaces of the spacer sticks when the spacersticks are supported on the first and second conveyors whereby axialmovement of the spacer sticks is prevented when the at least firstconveyor is displaced laterally to its release position.
 25. Theapparatus as claimed in claim 24, wherein a hold down member is providedto prevent longitudinal displacement of the spacer sticks when at leastone of the first and second conveyors are laterally displaced to itsrelease position.
 26. The apparatus as claimed in claim 24, wherein saidat least one elongated member includes two elongated stop bars providedin connection with opposite end surfaces of the spacer sticks when thespacer sticks rest on the first and second conveyors, the stop barsbeing located, in the vertical direction, so as to permit passage,beneath the stop bars, of the conveyors when the conveyors are laterallydisplaced to their release positions, but to be hit by the end surfacesof the spacer sticks if one or more of the spacer sticks were toaccompany such lateral movement.
 27. The apparatus as claimed in claim24, wherein an elongated slide rail is provided over the board stack andsubstantially in parallel with the first conveyor when in transportposition, said slide rail being located vertically such that, when thesecond conveyor has been displaced to its release position and thesecond end portions of the spacer sticks originally supported on thesecond conveyor have fallen down onto the board stack, the first endportions of the spacer sticks are supported on the slide rail instead ofon the first conveyor, said slide rail being laterally displaceabletogether with the first conveyor.
 28. An apparatus for placing aselectable number of spacer sticks with selectable mutual distance ontop of a board stack, the apparatus comprising: a feeder device forindividually feeding spacer sticks with selectable rate of feeding, thefeeder device being located in association with an end of the boardstack; a conveyor device configured to receive the spacer sticks as fedby the feeder device and to transport the spacer sticks, with aselectable speed of transportation, to locations above their intendedlocations on top of the board stack; the conveyor device having at leastone first and one second conveyor, the conveyors being located, intransport positions, above the board stack and along its opposedlongitudinal sides for supporting opposite end positions of the spacersticks, the first and second conveyors being laterally displaceableapart to release portions where the spacer sticks may pass between saidfirst and second conveyors to their intended positions in top of theboard stack.
 29. The apparatus as claimed in claim 28, wherein a holddown member is provided to prevent longitudinal displacement of thespacer sticks when at least one of the first and second conveyors arelaterally displaced to its release position.
 30. The apparatus asclaimed in claim 28, wherein two elongated stop bars are provided inconnection with opposite end surfaces of the spacer sticks when thespacer sticks rest on the first and second conveyors, the stop barsbeing located, in the vertical direction, so as to permit passage,beneath the stop bars, of the conveyors when the conveyors are laterallydisplaced to their release positions, but to be hit by the end surfacesof the spacer sticks if one or more of the spacer sticks were toaccompany such lateral movement.
 31. The apparatus as claimed in claim28, wherein an elongated slide rail is provided over the board stack andsubstantially in parallel with the first conveyor when in transportposition, said slide rail being located vertically such that, when thesecond conveyor has been displaced to its release position and thesecond end portions of the spacer sticks originally supported on thesecond conveyor have fallen down onto the board stack, the first endportions of the spacer sticks are supported on the slide rail instead ofon the first conveyor, said slide rail being laterally displaceabletogether with the first conveyor.
 32. A method for placing a selectablenumber of spacer sticks with selectable mutual distances on top of aboard stack having first and second longitudinal sides and first andsecond ends, the method comprising: individually feeding spacer stickswith a selectable rate of feeding to a conveyor device, said spacersticks being fed via a feeder device located in association with thefirst end of the board stack; receiving said spacer sticks onto theconveyor device provided above the board stack and configured to receivethe spacer sticks as fed by the feeder device, wherein the conveyordevice has at least one first and one second conveyor, each having upperand lower runs, the first and second conveyors being, in transportpositions, located above the board stack and along opposite longitudinalsides thereof for supporting, on their upper runs, opposite end portionsof the spacer sticks; transporting the spacer sticks with a selectablespeed of transportation to locations above the spacer sticks intendedlocations on the board stack; and displacing the first and secondconveyors laterally apart to release positions where the spacer sticksare free to pass downwardly between said first and second conveyors forplacement at their intended positions on top of the board stack.
 33. Amethod for placing spacer sticks on top of a board stack, comprising:individually feeding spacer sticks to a conveyor device, said spacersticks being fed via a feeder device located at an end of the boardstack; receiving said spacer sticks as fed by the feeder device onto theconveyor device; transporting the spacer sticks to locations above thespacer sticks intended locations on top of the board stack, wherein theconveyor device has at least one first and one second conveyor, theconveyors being located, in transport positions, above the board stackand along its opposed longitudinal sides for supporting opposite endportions of the spacer sticks; and displacing the first and secondconveyors laterally apart to release positions where the spacer sticksmay pass between said first and second conveyors for placement of thespacer sticks at their intended positions on top of the board stack. 34.A method for placing spacer sticks on top of a board stack comprising:individually feeding spacer sticks to a conveyor device, said spacersticks being fed via a feeder device being located at an end of theboard stack, wherein the conveyor device has at least one first and onesecond conveyor, the conveyors being located, in transport positions,above the board stack and along its opposed longitudinal side forsupporting opposite end positions of the spacer sticks; receiving saidspacer sticks as fed by the feeder device onto the conveyor device;transporting the spacer sticks to locations above the spacer sticksintended locations on top of the board stack; displacing the first andsecond conveyors laterally apart to release positions where the spacersticks may pass between said first and second conveyors for placement ofsaid spacer sticks to their intended positions on top of the boardstack; and preventing axial movement of the spacer sticks when the atleast first conveyor is displaced laterally to its release position byway of at least one elongated stop member arranged along at least thefirst conveyor and in alignment with the end surfaces of the spacersticks when the spacer sticks are supported on the first and secondconveyors.